Watch the dam movie
January 17, 2011 § Leave a comment
According to the Bureau of Meteorology, in the whole month of January, the city of Toowoomba expects to receive 60mm of rainfall. In the first sixteen days of January 2011, Toowoomba had recorded more than 400mm. All that water (and that was only a little bit of what fell on South East Queensland) had to go somewhere.
The historical graph of dam levels at Wivenhoe shows that, whenever the dam exceeds “normal” full capacity – ie 100% – water is released. But in that fateful week, the dam rose from 102.4% on Wed 4 Jan, to 148.4% on Mon Jan 10, to 188.5% on Thu 13 Jan. The natural deluge that caused all hell to break loose happened on that Monday. One analyst is asking why the dam levels weren’t lowered by then – nearly a week after full capacity had been reached. A few days later the dam was at dangerously high levels and very near to exceeding its flood compartment and triggering its own safety valves.
You don’t want a dam in charge of itself.
All this reading about how close Wivenhoe Dam came to losing it has got me thinking:
Is it time for a dam disaster movie?
How’s this pitch? A huge city toils 50 kilometres (okay, miles) downstream from its massive water supply. Greedy developers have crammed dwellings on every square metre (er, foot) of riverfront land. Millions of people go about their daily lives largely unaware of the dam’s existence. The dam’s engineers are first pumped, and then increasingly nervous, as extraordinary rainfall upstream takes the dam to alarming levels. Eighty, ninety, one hundred per cent of capacity, and then some, filling the built-in overflow capacity. A hundred and twenty, one-fifty, one hundred and eighty per cent. There are signs of strain in the two kilometres (miles) of spillway and billions of cubic metres (feet) of concrete and earth holding it back. A warning light here. A crack there. A black needle in the red zone. But the mayor, and the premier (governor), with their fingers deep in the lucrative, watery foundations of the city, don’t want to hear about it. There’s a once in a lifetime storm coming. Cue the catastrophe…
Anyway, here’s to Wivenhoe Dam and its amazing ability to keep 2.6 million megalitres of water behind a concrete wall. And may the frightening, tragic, brutal and downright messy events of January 2011 never happen again.
Except in a cinema near you.